Roller Brake Tester: Your Guide to Effective Vehicle Braking Assessment

An HGV roller brake test (RBT) is a controlled and safe way to measure the performance of a heavy goods vehicle's braking system. Here's a breakdown of how it works:

The Setup:

1. The Roller Bed: The vehicle is driven onto a platform with two sets of rollers underneath 1 axle at a time. These rollers are powered by electric motors and have a textured surface to simulate real-road conditions.
2. Measurements and Information: The tester enters the vehicle information (weight, axle configuration) into the system.  
3. Preparing the Vehicle: Brakes are checked for leaks or damage, and tyre pressure is adjusted if needed.

The Test:

1. Roller Activation: The rollers start spinning at a specific speed depending on the test requirements.
2. Brake Application: The driver applies the brakes following specific instructions (e.g., full force for service brake test).
3. Force Measurement: As the wheels slow down, the rollers resist their rotation, creating a force measured by sensors. This is referred to as the DTP (Decelerometer Test Point).
4. Data Collection: The system records the braking force for each wheel, total vehicle deceleration, and other parameters such as percentage efficiency.

The Analysis:

1. Performance Evaluation: The recorded data is compared to regulations and manufacturer specifications to assess the braking performance.
2. Individual Wheel Analysis: Each wheel's braking force is checked for imbalance, indicating potential issues.
3. Report Generation: A detailed report is generated, summarizing the test results and pass/fail status.

Additional Points:

• HGV roller brake tests can measure different types of brakes, including service brakes, parking brakes, and emergency brakes.
• Advanced tests can assess brake fade (performance over time) and ovality (trucks: uneven braking due to warped discs).
• These tests are crucial for ensuring the safety of HGVs on the road and are often mandatory for annual inspections and after brake repairs.